基于0.25μm BCD工艺的一种新型低温漂欠压保护电路

A New Low Temperature Drift Under-Voltage Protection Circuit Based on 0.25μm BCD Process

提出了一种结构简单并且具有低温度敏感性的新型欠压保护电路。该电路避免了传统欠压保护电路的基准电压产生模块和比较器模块,利用带隙基准结构和高阶温度补偿的方法减小阈值电压和迟滞电压随温度的变化量,提高了UVLO电路的独立性和可靠性。基于0.25μm BCD工艺设计实现的新型欠压保护电路芯片面积为0.04 mm^(2),功耗为0.14 mW。在温度为25℃时,新型欠压保护电路的上升阈值为8.625 V,下降阈值为8.145 V,迟滞量为0.48 V,能够满足电源管理芯片的应用要求。在-40℃~125℃温度变化范围内,该电路的阈值电压和迟滞电压的最大变化量分别为53 mV和50 mV,具有低温度漂移特性。

A novel under-voltage lockout circuit with simple structure and low temperature sensitivity is proposed.This circuit avoids the reference voltage generation module and the comparator circuit of the traditional under-voltage lockout circuit,but uses the bandgap reference structure and high-order temperature compensation to reduce the variation of threshold voltage and hysteresis voltage with temperature,thereby improving the independence and stability of the UVLO circuit.Based on the 0.25μm BCD process design,the new under-voltage lockout circuit has a chip area of 0.04 mm^(2) and a power consumption of 0.14 mW.The rising threshold is 8.625 V,the falling threshold is 8.146 V,and the amount of hysteresis is 0.479 V at 25℃,which shows that this circuit can meet the application requirements of power management chips.Within the temperature range of-40℃~125℃,the maximum change of threshold voltage and hysteresis voltage are 53 mV and 50 mV respectively,which indicates that the proposed under-voltage lockout circuit has low temperature drift characteristics.